小鼠腹腔巨噬细胞PAF受体放射配基受体结合分析方法

Establishment of PAF receptor radioligand binding assay in mouse peritoneal macrophages

目的 建立简便、快速的小鼠腹腔巨噬细胞PAF放射配基受体结合分析法 ,考察巨噬细胞表面PAF受体的特性。方法 以♂C5 7BL/ 6小鼠腹腔巨噬细胞为受体材料 ,[3 H] PAF为标记配基 ,非膜过滤法进行结合放射配基分离 ,液闪计数测定。结果 小鼠腹腔巨噬细胞PAF受体结合符合简单单位点受体结合模型 ,Scatchard分析求出的PAF受体结合参数Bmax=10 0 2fmol·1× 10 6cells-1,KD=3 2nmol·L-1。 [3 H] PAF与小鼠腹腔巨噬细胞PAF受体的结合呈现单一、饱和特点 ,并可被特异性PAF受体拮抗剂BN5 2 0 2 1竞争性抑制。结论 利用小鼠腹腔巨噬细胞贴壁特性 ,采用非滤过法处理细胞 ,能够在保持受体生理学活性的状态下 。

AIM To establish radioligand binding assay of PAF (platelet activating factor) receptors in mouse peritoneal macrophages and observe the characteristics of PAF receptors. METHODS PAF receptor radioligand binding was studied in intact adherent mouse peritoneal macrophages by -PAF. The radioactivity was counted with an LS6500 scintillation system. RESULTS The PAF receptor binding was shown to be saturable with an equilibrium K D of 3.2 nmol·L -1 and a B max of 100.2 fmol·1×10 6 cells -1. The competitive analysis showed that such specific binding could be inhibited by BN52021. CONCLUSION Utilizing the adherent character of macrophages, the binding ligands could be separated from non-binding ligands without negative pressure filtration, then cells could reserve fine activity, and PAF receptors could be near to physiological properties for screening of PAF antagonist.